Good stuff, Robb.
Reading a lot about IF over the last week, and evaluating my purpose behind following some IF protocol has solidified some of my positions.
I want primarily to lean out. I carry a fairly large amount of muscle mass as it is. Adding more wouldn't be bad, but I really want to decrease bodyfat. So, unless I see a performance drop, I am going to train while in a fasted state, and then continue the fast for 30 minutes to an hour after training, primarily to cool down, clean up, etc. If I do see a performance drop, then I will start by taking in small amounts of protein prior to training.
My fasts have been from 17 to 19 hours long, and Tuesday, 23-May will mark a week of following the IF (I did take Sunday off the fasting, though). I am working on the quality of the food eaten during the "feasting" window.
I am tracking bodyweight, umbilical circumference, and an abdominal skinfold, to keep a more objective eye on body comp changes.
So far the hunger hasn't been unbearable. I have visibly leaned out in my face and a bit in the stomach, though the scale doesn't reflect much more that a 1-2 lb weight loss. My energy levels have been very good. Workout performance hasn't suffered, though I do tend to crash after I break the fast.
One interesting thing, though, is that some knee pain I usually live with has faded. I can't separate the cause of the fading from a change in my "knee lube" regimen or the IF, but I have a feeling the fasting may have reduced some of the overall levels of inflammation. I haven't dug into that fully yet, but it's a nice side effect, no matter what caused it.